off('load') then on('load') does not work using setStyle

Nobody has claimed this yet.

**mapbox-gl-js version**:
v2.4.0

**browser**:
Chrome Version 92.0.4515.159

### Steps to Trigger Behavior

Reproduce steps
1. add `Map.on('load', func)`
2. add `Map.off('load', func)`
3. add `Map.on('load', func2)`
4. call `Map.setStyle()`

### Link to Demonstration

https://jsfiddle.net/tsuzk/6o8m9nad

This should work because of [this test](https://github.com/mapbox/mapbox-gl-js/blob/v2.4.1/test/unit/ui/map.test.js#L136-L151)

### Expected Behavior

The `Map.on('load', func2)` should get called after `Map.setStyle()`

### Actual Behavior

The `Map.on('load', func2)` does not get called after `Map.setStyle()`

### Workaround

re-instantiate the map with a new stlye https://jsfiddle.net/tsuzk/6o8m9nad/1/

### Other info

- This occurs on v1.9.0 so it's not a new behavior in v2.

### Priority

Low, since there is a proper workaround

Start with test/unit/ui/map.test.js, especially the linked load-listener test, and reproduce the issue using the provided JSFiddle steps around Map.on, Map.off, and Map.setStyle. Trace the relevant map event and style-reset behavior. Done means the second load callback is invoked after setStyle without requiring a new map instance.

Written by the indexing model from the issue text.